Why did Tito’s get me so drunk.

My friend and I were drinking Tito’s vodka last night and we noticed we were getting excessively drunk. We had only taken a few swigs from the bottle (3 or 4). As soon as we took the shot, we felt super sick. After a couple seconds we felt the effects of the vodka but they were super strong. My friend doesn’t usually puke after she drinks but we both did even though we barely drank anything. It’s also very unusual for us to get this drunk off of only 3 shots. We are also hungover the next morning and we literally never get hungover. Is something wrong with the vodka? Could someone tell me what could be, because we are so confused.